Composite material

ABSTRACT

The invention relates to a composite material, made from a microfilament nonwoven fabric having a mass per unit area of 40 to 200 g/m 2 , in which a nonwoven fabric, which is made from melt-spun, drawn, multi-component endless filaments having a titer of 1.5 to 5 dtex and directly laid up to form a fibrous web, and in which the multi-component endless filaments, optionally after prebonding, are split at least to 80% to form micro-endless filaments having a titer of 0.1 to 1.2 dtex and bonded, is bonded to a thermoplastic synthetic material using an injection-molding process.

[0001] The invention relates to a composite material, made from amicrofilament nonwoven fabric having masses per unit area of 50 to 200g/m², which is bonded with a thermoplastic synthetic material directly,using an injection-molding process.

[0002] Paneling parts for automobile interiors are known from thedocument EP 0 968 806, whereby a microfiber nonwoven fabric is placedinto a mold and bonded to a thermoplastic synthetic material by aninjection-molding process. Such injection-molding or “direct injectionmolding” (DIM) processes permit efficient production of paneling partsin the automobile interior sector. The microfiber nonwoven fabric ispreferably made from polyester fibers that function as a binding layerfor a decorative layer that is applied subsequently.

[0003] In the course of ever greater requirements in the automobileindustry, new demands are being made on the suppliers. For example, thepaneling parts used in the interior of the automobile are supposed todemonstrate attractive optical and sensory properties of the decor. Theparts are supposed to be capable of recycling, to possess a very highlevel of resistance to color fading, especially under the effects ofblack-panel temperatures, a low tendency to become dirty, a high levelof friction wear resistance, moisture resistance, fire resistance,cleanability, a low tendency or no tendency to emit gases, and lowcosts. Furthermore, efficient, cost-effective production methods for theproduction of the paneling parts are aimed at.

[0004] The invention has set itself the task of indicating a compositematerial, as well as a method for its production, that take into accountthe stated requirements.

[0005] According to the present invention, the task is accomplished by acomposite material that is made from a microfilament nonwoven fabrichaving a mass per unit area of 50 to 200 g/m², the nonwoven fabric beingmade from melt-spun, drawn multi-component endless filaments having atiter of 1.5 to 5 dtex and directly laid up to form a fibrous web, andthe multi-component endless filaments, optionally after prebonding,being split up to at least 80% to form micro-endless filaments having atiter of 0.1-1.2 dtex, and bonded, and then bonded to a thermoplasticsynthetic material using an injection-molding process. The compositematerial demonstrates a high level of specific fiber surface at acomparatively low mass per unit area, as well as high opacity. Thefineness of the filaments permits good printability and embossability,and thereby decorative structuring of the nonwoven fabric used for theproduction of the composite material according to the invention. In thisconnection, the thermoplastic synthetic material does not impregnate thenonwoven fabric.

[0006] Preferably, the composite material is one in which the nonwovenfabric is made from melt-spun, aerodynamically stretched multi-componentendless filaments having a titer of 1.5 to 3 dtex and directly laid upto form a fibrous web, and the multi-component endless filaments aresplit up to at least 80% to form micro-endless filaments having a titerof 0.1 to 0.3 dtex, and bonded. The composite material demonstrates anisotropic filament distribution in the web, making further processingrelatively independent of the machine running direction and thereby veryadvantageous for material utilization.

[0007] Preferably, the composite material is one in which themulti-component endless filament is a bicomponent endless filament madefrom two incompatible polymers, particularly a polyester and apolyamide. Such a bicomponent endless filament demonstrates goodsplittability into micro-endless filaments and results in anadvantageous ratio of strength to mass per unit area. At the same time,the composite material according to the invention is very easy to cleanand wipe down, because of the polymers used and their filamentstructure, and demonstrates a high level of wear resistance, i.e. it iseasy to take care of.

[0008] Preferably, the composite material is one in which themulti-component endless filaments have a cross-section having anorange-like multi-segment structure, also called a “pie” structure, thesegments alternately containing one of the two incompatible polymers ineach case. In addition to this orange-like multi-segment structure ofthe multi-component endless filaments, a “side-by-side” (s/s) segmentarrangement of the incompatible polymers in the multi-component endlessfilaments is also possible, which arrangement is preferably used for theproduction of crimped filaments. Such segment arrangements of theincompatible polymers in the multi-component endless filament haveproven to be very easy to split. The nonwoven fabric used for theproduction of the composite material according to the inventionpossesses a good deep drawing capacity, or deformability, which isexpressed in the average strength values at a high expansion capacityand comparatively low modulus values.

[0009] Preferably, the composite material is furthermore one in which atleast one of the incompatible polymers forming the multi-componentendless filament contains an additive, such as color pigments,permanently acting anti-statics, flame retarding agents and/or additivesthat influence the hydrophobic properties, in amounts up to 10 percentby weight. Static charges can be reduced or prevented with theadditives, and the lightfastness of the surfaces visible in theautomobile interior on exposure to a high black-panel temperature can beimproved. Using overdyed products, values for lightfastness underblack-panel temperatures of ≧6 have been achieved, determined accordingto DIN EN 20105-A02.

[0010] The method according to the invention, for the production of acomposite material, is made up of the steps that multi-component endlessfilaments are spun from the melt, stretched, and directly laid up toform a web, that prebonding takes place, and that the nonwoven fabric isbonded using high-pressure fluid jets, and, at the same time, split intomicro-endless filaments having a titer of 0.1 to 1.2 dtex, and bonded toa thermoplastic synthetic material by an injection-molding process. Thecomposite material obtained in this way can be produced in very shortcycle times. The cycle times can be reduced from approximately 50 to 2to 5 seconds, as compared with known composite components.

[0011] It is advantageous that the method for the production of thecomposite material is carried out in such a manner that themulti-component endless filaments are bonded and split in that thenonwoven fabric, which has been prebonded if necessary, is impacted atleast once on each side with high-pressure water jets, and placed intoan injection-molding mold after a drying process, and backed with athermoplastic synthetic material by injection-molding. As a result, thecomposite material demonstrates a good surface and a degree of splittingof the multi-component endless filaments >80%.

[0012] Advantageously, the nonwoven fabric used in the compositematerial according to the invention is subjected to spot calandering inorder to increase its friction wear resistance. For this purpose, thesplit and bonded nonwoven fabric is passed through heated rollers, atleast one of which has elevations that result in melt-bonding of thefilaments to one another at certain points.

[0013] Because of its properties, such as good printability, a highlevel of friction wear resistance, as well as its good lightfastnessunder black-panel temperatures, and its haptic properties, the nonwovenfabric used for producing the composite material according to theinvention is suited for the production of door, pillar, and/or trunklinings, rear window shelves, car roof linings, dashboards, as well aswheel house liners.

EXAMPLE 1

[0014] A filament sheet having a mass per unit area of 134 g/m² isproduced from a side-by-side (s/s) polyester-polyamide 6.6 (PES-PA6.6)bicomponent endless filament having a titer of 2.3 dtex and a weightratio of PES/PA6.6 of 60/40, and is subjected to water-jetneedlepunching at pressures up to 230 bar, on both sides. Thebicomponent endless filaments have a titer of 1.0 dtex and a thicknessof 0.51 mm after the water-jet needlepunching process, which results insplitting of the starting filaments at the same time. Values of 372 N inthe machine running direction and 331 N in the crosswise direction weredetermined for the tear strength.

EXAMPLE 2

[0015] A filament sheet having a mass per unit area of 137 g/m² isproduced from a side-by-side (s/s) polyester-polyamide 6.6 (PES-PA6.6)bicomponent endless filament having a titer of 1.8 dtex and a weightratio of PES/PA6.6 of 50/50, and is subjected to water-jetneedlepunching at pressures up to 230 bar, on both sides. Thebicomponent endless filaments have a titer of 1.0 dtex and a thicknessof 0.52 mm after the water-jet needlepunching process, which results insplitting of the starting filaments at the same time. Values of 457 N inthe machine running direction and 373 N in the crosswise direction weredetermined for the tear strength.

EXAMPLE 3

[0016] A filament sheet having a mass per unit area of 105 g/m² isproduced from a 16 segment (pie) polyester-polyamide 6.6 (PES-PA6.6)bicomponent endless filament having a titer of 2.4 dtex and a weightratio of PES/PA6.6 of 55/45, and is subjected to water-jetneedlepunching at pressures up to 230 bar, on both sides. Thebicomponent endless filaments have a titer of 0.1 dtex after thewater-jet needlepunching process, which results in splitting of thestarting filaments at the same time, and a thickness of 0.48 mm after afinal smoothing process. Values of 302 N in the machine runningdirection and 303 N in the crosswise direction were determined for thetear strength.

EXAMPLE 4

[0017] A filament sheet having a mass per unit area of 244 g/m² isproduced from a 16 segment (pie) polyester-polyamide 6.6 (PES-PA6.6)bicomponent endless filament having a titer of 2.1 dtex and a weightratio of PES/PA6.6 of 70/30, and is subjected to water-jetneedlepunching at pressures up to 230 bar, on both sides. Thebicomponent endless filaments have a titer of 0.1 dtex after thewater-jet needlepunching process, which results in splitting of thestarting filaments at the same time, and a thickness of 0.90 mm after afinal smoothing process. Values of 763 N in the machine runningdirection and 739 N in the crosswise direction were determined for thetear strength.

EXAMPLE 5

[0018] A filament sheet having a mass per unit area of 131 g/m² isproduced from a 16 segment (pie) polyester-polyamide 6.6 (PES-PA6.6)bicomponent endless filament having a titer of 2.0 dtex and a weightratio of PES/PA6.6 of 70/30, and is subjected to water-jetneedlepunching at pressures up to 230 bar, on both sides. Thebicomponent endless filaments have a titer of 0.1 dtex after thewater-jet needlepunching process, which results in splitting of thestarting filaments at the same time, and a thickness of 0.53 mm after afinal smoothing process. Values of 309 N in the machine runningdirection and 284 N in the crosswise direction were determined for thetear strength.

What is claimed is:
 1. A composite material made from a microfilamentnonwoven fabric having masses per unit area of 50 to 200 g/m², thenonwoven fabric being made from melt-spun, drawn, multi-componentendless filaments having a titer of 1.5 to 5 dtex and directly laid upto form a fibrous web, and in which the multi-component endlessfilaments, optionally after prebonding, are split at least to 80% toform micro-endless filaments having a titer of 0.1 to 1.2 dtex andbonded, and is bonded to a thermoplastic synthetic material using aninjection-molding process.
 2. The composite material as recited in claim1, wherein the nonwoven fabric is made from melt-spun, aerodynamicallystretched multi-component endless filaments having a titer of 1.5 to 3dtex and directly laid up to form a fibrous web, and the multi-componentendless filaments, optionally after prebonding, are split to at least80% to form micro-endless filaments having a titer of 0.1 to 0.3 dtex,and bonded
 3. The composite material as recited in claim 1 or 2, whereinthe multi-component endless filament a bicomponent endless filament madefrom two incompatible polymers, particularly a polyester and apolyamide.
 4. The composite material as recited in one of claims 1through 3, wherein the multi-component endless filaments have across-section having an orange-like multi-segment structure, thesegments in each case alternately containing one of the two incompatiblepolymers and/or having a “side-by-side” structure.
 5. The compositematerial as recited in one of claims 1 through 4, wherein at least oneof the incompatible polymers forming the multi-component endlessfilament contains an additive, such as color pigments, permanentlyacting anti-statics, flame retarding agents and/or additives thatinfluence the hydrophobic properties, in amounts up to 10 percent byweight.
 6. A method for producing a composite material as recited in oneof claims 1 through 5, wherein multi-component endless filaments arespun from the melt, stretched, and directly laid up to form a web,prebonding is optionally carried out, and the nonwoven fabric is bondedusing high-pressure fluid jets, and, at the same time, split intomicro-endless filaments having a titer of 0.1 to 1.2 dtex, and bonded toa thermoplastic synthetic material using an injection-molding process.7. The method as recited in claim 6, wherein the multi-component endlessfilaments are bonded and split in that the nonwoven fabric, which hasbeen prebonded if necessary, is impacted at least once on each side withhigh-pressure fluid jets.
 8. The method as recited in claim 6 or 7,wherein the multi-component endless filaments are dyed by spin-dyeingand/or overdyeing.
 9. The method as recited in one of claims 6 through8, wherein the nonwoven fabric for the production of the compositematerial is spot-calandered.
 10. The composite material as recited inone of claims 1 to 9, wherein it is used for the production of door,pillar, and/or trunk linings, rear window shelves, car roof linings,dashboards, as well as wheel house liners.